


DATING START!

by MeGaLoTrash



Category: Undertale (Video Game)
Genre: Confessions, Cunnilingus, Dirty Talk, Dry Humping, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Ectobiology, Explicit Language, Explicit Sexual Content, Fingering, Fontcest, Loss of Innocence, M/M, Masturbation, NSFW, Oral Sex, Sex, Sexual Fantasy, Sibling Incest, Voyeurism, attempts at bad jokes, mild restraints, puns, terrible puns
Language: English
Status: Completed
Published: 2017-06-21
Updated: 2017-06-29
Packaged: 2018-11-17 03:37:12
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 11,222
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11267145
Author URL: https://archiveofourown.org/users/MeGaLoTrash/pseuds/MeGaLoTrash
Summary: Set in a first time Pacifist Run, Papyrus going on a fake 'Date' opens up a can of worms. 1/3 parts, this one is more on the fluffy side, it won't stay that way in part 2/3 ;). (Edited for mistakes- thanks for pointing some out @Rush_Toward ^.^)





	1. Part 1

Dating was a first.

 

Sans had experienced many encounters with the human that he could remember, he had learnt to keep a very watchful eye on their first interactions with him and his brother to be able to judge how it was going to go. Most of the time the child willingly went along with the puzzles, laughed along at his jokes and left Snowdin with a cheerful wave and promises to stay out of trouble. There had been times though where Sans was fooled by their innocence and he ended up having to teach that dirty brother killer a lesson- but today was defiantly not one of those times. 

 

From the get go the kid seemed kinder than usual, more than happy to play along and hide behind the convenient lamp he had found. As the day went on they seemed to be genuinely enjoying themselves; laughing at his bad jokes, rising to Papyrus's challenges, hell they even came to talk to him a few times after Papyrus had ran off to set up the next puzzle. A part of him knew it was foolish to put his trust in the kid this soon, but he couldn't help it- it didn't seem like the kid had a mean bone in his body. Pun intended. So much so that when it came for the 'final fight' between the kid and his brother he chose taking it easy and hanging back in the living room half watching from the window rather than his usual hiding spot. He knew how this one would go, the kid would play Papyrus's games, dodge his attacks all the while weakening his brother's resolve to fight. Papyrus may act all high and mighty but underneath the façade he was the kindest guy Sans knew and he nurtured that part of him and tried to protect him from harm. 

 

_And protect him from you_ , his thoughts reminded him. He couldn't deny that his admiration of his brother had often strayed to less than brotherly thoughts. It wasn't a secret that Sans was a flirt and a bit of a freak... and there was something about the corruption of innocence that was so intoxicating to him. But his moral compass prevented him from actually acting upon his dirty fantasies; no matter how much he wanted to bring his pious brother to his knees he'd never do so without his willingness or consent. And he somehow doubted it would be forthcoming. To his knowledge Papyrus had not so much as looked at another monster with romantic intent, he was almost 100% sure his brother had never done anything sexual in the slightest even with himself- but that didn't stop sans thinking about that particular fantasy most nights. He imagined the blush that would cover Papyrus's cheeks as he explored himself for the first time, the moans that would spill from his mouth as he discovered his most sensitive points, and the inability to keep quiet as his magic formed and he let those long fingers of his bring him to completion. Sans would get so wrapped up in his fantasies he would swear blind he could even hear the noises some nights, often accompanied with muffled calls of his own name as he fisted himself inside his shorts. Safe to say Sans had a active imagination.

 

Yeah, he was pretty sure the only thing Papyrus had even come close to a romantic attraction was the first few weeks after he discovered the MTT show on T.V.- a crush that had fizzled as soon as it came on after he decided the robot was far to self-centered for his standards and that it was an aesthetic attraction at most. This was one of the reasons Sans was so sure of his brother's innocence as he was told in detail about everything his brother knew about the robot even when they were watching the same show, so he was sure that any actual relationships or interactions he had with others his brother wouldn't be able to keep a secret. 

 

Sans thought that the brief infatuation his brother had with the robot should have made him envious but honestly it had only spurred his want for him on more. It was when Papyrus was telling him over dinner one evening about a MTT show he had caught earlier about the robot's daily life that he first discovered the light orange blush his brother would get when talking about something he liked. He wasn't even talking about anything in particular that Sans could remember; but Papyrus was so expressive it gave any emotion he was feeling away. Sans had seen the blush before but there was just something about the way he was talking with a slight uncertainty about it and the fact he couldn't quite hold eye contact that had Sans' immediate attention and he had that expression burned into his memory. He had manage to pull that expression from Papyrus a few times since, with a few lewd jokes or the time where he'd 'accidentally' tripped over the sock in the living room and into his brother's arms when he had been yelling at him for leaving it there. Fuck, the look he'd given him then when he was that close to his face was enough for Sans to vow to never pick up the sock again for the chance to see it that expression more. He could feel himself getting hard just from remembering how quickly Papyrus had switched from his usual confident demeanour to the shy, blushing skeleton quivering at his touch. 

 

He had been so caught up thinking about the things he would have done if given half a chance that he literally jumped in the air when his brother came crashing through the door. 

 

“BROTHER, I HAVE DECIDED THAT I, THE GREAT PAPYRUS CANNOT CAPTURE THE HUMAN!” Papyrus proudly exclaimed, hands on his hips in a triumphant pose. Sans had the sense to pull his hoodie down immediately hiding anything that hadn't gone away with the shock before questioning him why, though he already knew the answer would be along the lines of not wanting to hurt the innocent.

 

“why is that bro, don't you need to capture them for undyne?'

 

“I JUST CANNOT BRING MYSELF TO HARM OR CAPTURE ANYONE WHO SHOWS NO INTENT TO FIGHT. I'M SURE UNDYNE WILL UNDERSTAND, SHE HAS ALWAYS TAUGHT ME TO PROTECT THE INNOCENT!” 

 

Bingo. Sans feigned shock at the revelation and gave a reassuring “i'm sure she will bro.” he was lucky that he could do this interaction in his sleep as his brain hadn't quite caught up with the situation, which made the following conversation all the more jarring. 

 

“BESIDES-” Papyrus had started before his voice dropped “I Can't Very Well Capture Someone When They've Asked Me, The Great Papyrus, On A DATE!”

 

Sans should have picked up on the lowering of his brother's voice that there was something different about the exchange but it hit him like a ton of bricks, his mouth asking questions before he had time to process.

 

“b-bro, you do know that a child is a young human, like a babybones, you can't actually-”

 

“FEAR NOT DEAR BROTHER, I AM AWARE THAT IT IS NOT A 'REAL' DATE, I AM MEARLY ENTERTAINING THE HUMAN IN A PLATONIC FAKE DATE!” 

 

Sans audibly sighed at himself, of course it wasn't a real date, he felt so bad about underestimating his brother's understanding that he almost missed what was said next-

 

“IN FACT- THE GREAT PAPYRUS HAS NEVER BEEN ON ANY KIND OF DATE- T-That Is To Say, I-I Thought It Would Be Good Practice For When-” Papyrus trailed off. 

 

“when what?”

 

“When-W-Well, I Mean, We- ME- I-IAM SORRY SANS I HAVE TO GET READY FOR THE DATE”

 

That flustered look was back and Sans could see his blush was more prominent than he'd ever seen before. The air suddenly felt heavy as Papyrus began frantically looking around for something to tidy up before the human arrived. Sans was frozen in Place as he tried to think what the Hell his brother had been trying to say. Was he talking about wanting practice to date someone else? Why did he stop himself from explaining? Why did the atmosphere get so tense and full with things Papyrus had tried to avoid? And why was he now running around pretending to clean but not getting anything actually done? _What the hell had just happened!?_

 

He made his excuses, something about leaving him to it and promptly re-appeared in his bedroom. It was all too much to process so leaving seemed like the right thing to do even if he felt bad about it; His control was slipping and it was a dick move but it was better than the alternative of saying something stupid. He audibly groaned sinking against his bedroom door, he knew he shouldn't be on the thought train he was on but it seemed his baser instincts were set on going there. He knew his brother was flustered, He knew it was over the prospect of dating someone for real, _He wanted that someone to be him. Fuck._

 

Sweat beads were forming on his skull as he heard Papyrus continue crashing about downstairs. He thought the distance from the object of his affections would help but it only sent his mind into overdrive; Call it wishful thinking somewhat but there was no way he had imagined the tension that sprang up between them. Even now with a whole floor and door separating them he was still overly aware of his brothers energy, and his head was filling in the blanks. He knew that flustered look would still be there, he knew with him upstairs that Papyrus's mask of confidence would be gone completely, that he was probably still a light shade of orange and was probably biting on his finger absent-mindedly like he did when he was worried about something. _What he wouldn't give to put that mouth to better use_ \- NO, now wasn't the time Sans told himself. The kid would be here any minute and he had to calm the fuck down and that trail of thought was getting him no where. 

 

Sans got to his feet and wiped his brow with the back of his hoodie sleeve. He thought briefly about using the dusty running machine in the centre of the room for it's intended purpose but he had to laugh, the situation was dire but not to the extent he'd do something like that. No, he'd want to try keep an ear out for anything from his room, the logical part of his brain reminding him that this was a new development from the kid and needed monitoring, just in-case. He decided that the edge of his bed would be a good place to eavesdrop, given the volume his brother usually talked in he shouldn't have any difficulty hearing what was going on, plus the disarray of sheets gave him something to steady his grip on as he tried to keep the shreds of his cool intact.

 

*******************************************************************************

 

To Sans' surprise he had managed to keep a level head. He'd even admit he was having fun; the kid was being adorable and he found it easy to slip into the annoying brother role easier having a third party there. Papyrus was having a great time leading them around a tour of the house and even cracking a few jokes, plus sans hadn't been able to resist using the trombone gag after that dog had managed to get under the sink again. He was pleased to hear Papyrus had yelled at him back as he shut the door. _Good, maybe they can just forget the whole thing_ he thought, but knew Papyrus wasn't one to let things go unspoken; one of the drawbacks of wearing a heart on your sleeve he guessed.

 

_Yeah Pap is so open, tells you everything, but has been keeping whatever that was earlier from you. Maybe your brother isn't as naive as you think..._ He tried to stop the nagging thoughts bubble through while listening to their 'date' progressing next door but it was getting harder and harder to ignore, he knew his brother had been hiding something now and it was almost impossible for him to calm down enough to stop thinking about all the possibilities of what it could be. He got so wrapped up in his thoughts that again he almost missed something papyrus had said. It had been established that the kid really did have a bit of a crush on him, and he could hear his brother was starting to have doubts over them knowing for sure that It wasn't really a date. Picking up on the shift in his brother's tone and snapping out of his thoughts Sans sprung to his feet towards the wall separating them, pressing up against it so he could hear better. 

 

'-HOT IN HERE OR IS IT JUST ME? OH, SHOOT. HUMAN, I... I'M SORRY. I DON'T LIKE YOU THE WAY YOU LIKE ME. ROMANTICALLY, I MEAN' he heard him say, then he continued to try to let him down easily. 

 

Sans had to hand it too him, he could hear the conviction in his voice, he really didn't want to upset the kid and yet he was picking up something else in his speech. Every time he mentioned trying to date them to develop feelings he couldn't help pick up something weird in Papyrus's voice, the same weirdness he had picked up in his voice earlier, like he was hiding something.

 

He heard Papyrus usher the kid out the door, wishing them luck on their journey and even giving his phone number out to help them; making sure to to stress that it was in a friendly capacity only. Sans couldn't help the small smile he got listening to them both, after seeing the destruction that could have been caused it was amazing the connection they seemed to be making this time, he found himself actually looking forward to running into the kid further down the road. He may even go easy on the threats this time. 

 

The main door clicked shut and it seemed to change atmosphere almost immediately. He had no idea what to do. Should he sit and wait for Papyrus to come to him? Should he confront his brother by storming downstairs and demanding he told him everything? Should he teleport out of here and give himself time to get his head straight? No, that last idea would upset his brother and that was the furthest thing from what he wanted. He decided that he would just go down and act like nothing was wrong, wait for Papyrus to bring it up. _Or at least give him chance to talk before he bombarded him with a million questions._ Sans strode towards the door and flung it open only to find Papyrus stood there going to knock on the door himself.

 

“jesus papyrus, you almost made me jump out of my skin” he joked, noting that the delicious expression that had plagued his thoughts for the last few hours was back.

 

“BROTHER YOU DON'T EVEN HAVE SKIN!”

 

“noted, what's up?” 

 

“I Came To Talk To You About Earlier T-Today” 

 

“right, the thing you couldn't- it's ok if you don't want to talk about it-”

 

“THE TRUTH IS SANS, I-I HAVE BEEN WANTING TO ASK YOU ABOUT DATING FOR A WHILE NOW”

 

“well, you know you can come to me with anything bro, even if it's do with someone else- I mean-”

 

“ No Brother You're Not Getting What I'm Trying To Say, I've Wanting to Ask About, Er- The Possibility- I Mean If You'd Even Want To That is- And If You Don't That's Fine I Won't Make I Awkward- I -Erm-” 

 

Sans couldn't believe his ears, was his brother really trying to say what he thought? He could hear his soul pulsing through his body. Papyrus was so close to saying what had been bothering him but he couldn't quite get the words out, he needed to help out but he didn't want to mess up big time by assuming. He had to know though, he extended an almost steady hand out to his frantic brothers arm.

 

“papy” He caught the shudder at the use of the pet name through their contact “i need you to be really clear right now what it is you're asking-”

 

“Sans, I- I What I Mean To Ask, What I Want To Say R-Really Is-

 

“'cause it sounds an awful lot like you're asking me-”

 

“SANS I KNOW YOU KNOW WHAT I'M SAYING AND I KNOW YOU WANT TO DATE ME! I WANTED TO TELL YOU NOTHING WOULD MAKE ME HAPPIER- I- I'm Sorry It's Taken Me So Long To Tell You I Just Had To Be Sure I Was Ready- SANS I'M SORRY PLEASE SAY SOMETHING!”

 

If Sans could have been dusted by words alone this would have killed him 5000 times over. He knew there was a confession coming but he could have never expected that. _And that Papyrus knew what he thought about him._ He didn't have time to process anything, Papyrus had fully clung to his arms back now and with such intensity he was almost being lifted. He saw everything in his face, the worry he had scared his brother, the fear of rejection, the neediness of finally letting go and he was feeling it all too. But he couldn't leave him hanging while he thought carefully of what to say next, no he owed it to papyrus to be honest.

 

“papy- it's ok- sorry it just caught me off guard, how did you know?”

 

“The Walls Aren't Exactly Thick Sans” 

 

Papyrus had dropped his voice to a point where it was almost a whisper now and Sans could swear he saw a glimmer of a smirk there. So Papyrus knew, he knew a lot, and he wasn't disgusted with him. In fact it seemed like the opposite? He was interested enough in him to bring it up and practically ask him to date him even though he'd heard him touch himself through the walls. _Did that mean he hadn't imagined the noises coming from his brothers room?!?_

 

_Fuck._

 

“well- i- sorry papy, I didn't know you could hear me- whelp-”

 

“Really? I Thought You Would Know, I Haven't Exactly Been Silent Myself Lately. Hearing You Makes Me Feel... T-Things. I Know I Should Have Said Something Sooner But-”

 

_Fuckkkkkk_

 

“-But Honestly I Thought If You Heard Me You'd Come Into My Room Anyway. I-I Was Kind Of Hoping You Would...”

 

_Fucckkkkkkkkk._ Sans had lost all Coherent thought and had hardly realised he was stood staring at Papyrus literally with his jaw hanging open. Not only had the object of his affection- no obsession- admitted he liked him back but he was literally telling him about his fantasies and that _he had touched himself over him._ He couldn't help it, what started as a smirk turned into giggling which turned into him shaking with laughter in his brothers arms. What was this guy doing to him?

 

“SANS! NOW IS NOT THE TIME FOR JOKES!” Papyrus scolded him, letting go of his arms to fold his own in front of him.

 

“heh- sorry bro. really i-heh- am, it's just a lot to take in. i guess you could say it's really rattling my bones”

 

He couldn't help it, humour had always helped him in difficult situations.

 

“SANS!!”

 

“-heh sorry papy, really i am happy you told me, and i- heh- guess you already know i really want this too” 

 

Sans made sure to make eye contact with Papyrus then, inner turmoil aside he didn't want to ruin what could be the start of something between them for real. The realisation that all of it could be quickly snatched away from him with the unstable time issues made any uncertainty he felt dissipate. If he fucked it up between them Papyrus would never remember. He would hate himself for a long time but he wouldn't mess up the chance of happiness for his brother in this timeline. Unconsciously he had closed the gap between them and was bringing Papyrus down to his level by hands on his shoulders, he wanted the other skeleton to know he was serious.

 

“I Get It Sans, It's A Lot To Take In. But You're Sure? You Really Want To Be With Me?” 

 

The look on Papyrus's face had melted his resolve further as he let out a gasp at the sight. His brother really was so beautiful to him. Seen as words had escaped him again he decided to show his brother by leaning up and giving him a chaste kiss. He had planned it to be quick but he saw the other skeleton's eyes flutter closed and the hands that were still folded across his chest drop to wrap around him. He couldn't help his eyes become lidded with desire and his soul flip over the fact he was finally getting to kiss his brother. Something just short of a growl passed his lips when they finally parted, and he swore Papyrus had let out a small whine. His frayed nerves could barely hold back from pinning him to the wall and seeing what other noises he could pull from him. _No, I need to wait until he's ready, even if it kills me._

 

“i hope that answers your questions bro” he finally said in between shaky breaths. 

 

“Wowie! It certainly does Sans! I Never Knew Kissing Would Be That Much Fun! We Should Do It Again!”Papyrus exclaimed leaning in to embrace him again. 

 

“steady on there bro, w-we don't want to rush, it's been a big day for both of us- heh” Sans used the last of his resolve to pull away slightly but with a smile, he didn't want Papyrus to think the contact was unwanted but knew they both needed time to re-adjust.

 

“Y-Yes Sans You Are Right! I Don't Want To Do Anything Wrong And My Dating Guidebook Talked About Taking Things Slow! Will You Still Come Read Me A Bedtime Story Though?”

 

“Heh- Sure thing bro, just give me ten minutes and i'll be right in”

 

“OK SANS! If I Hear Anything From Your Room This Time Though-” Papyrus averted his eyes “I Won't Try To Keep Quiet Too” 

 

And with that Papyrus practically skipped off to his room leaving sans clutching at his door, now sporting his own blush and a growing swell in his pants. If there was a hell he was going straight to it, _and he was going to love every minute of it._


	2. Part Two: Electric Boogaloo

**Summary for the Chapter:**

> Part 2/3

Papyrus hummed happily to himself as he prepared dinner for himself and his brother. _Tonight will be the one_ he thought. He could lie and say the reason was that he had more time to prepare this evening with their home once again being empty for the night, but to be completely honest it was because he was being driven crazy by their nightly antics. He had no idea when they would have the house to themselves again which was a good enough reason. Undyne had insisted she was needed at the capital and Sans had been gone all day at one of his posts so as well as planning tonight Papyrus had a lot of time to think about recent events.

About a week ago he had finally built up the courage to somewhat confess his feelings and somewhat ask his brother if they could begin dating. Even if it hadn't been completely planned for him to finally tell Sans how he felt It felt wonderful to finally be able to be open about it and he could tell it was a huge relief to his brother as well. Sans seemed lighter, and a lot more approachable, and his lazy bones brother even seemed to be sleeping less in the day . Which was odd as papyrus knew for a fact he wasn't sleeping through the night: Neither of them were. 

The routine of their day to day life hadn't changed much in a week; he hadn't expected it too. Dating Sans felt natural as they were already close and spent a lot of there time together. They're had been a few more hugs than usual, a few lingering touches and goodbye kisses, and he had even been convinced to _nap_ one evening together after watching a MTT cooking special featuring the human. Overall it seemed they were able to fall into a comfortable closeness and he no longer worried about wanting to be more affectionate with Sans as he had before they had spoken about there feelings. He truly thought that they were making each other happy and that was all he wanted, it made his soul flutter thinking about them being together forever.

At night was a different story.

It started the first night after Sans had tucked him in, despite their confessions in the hallway and their first kiss it had seemed Sans had managed to gather himself and read his bedtime story as normal. Papyrus was thankful- feelings aside he didn't want to loose what he and his brother already had. The only difference was that when he had finished his story Sans moved his usual goodnight kiss from his forehead to lightly press their teeth together. Again there was a feeling of electricity between them and this time his brother had been the one to linger. When Papyrus had pulled away he saw a glimpse of his brothers facade slipping to enjoy their kiss, his eyes were lidded and the permanent smile he sported had become somewhat lax. With the way his brother was looming over him like that in the low light of his bedroom he looked almost _Predatory_. Papyrus didn't have time to enjoy that image as Sans was quickly backing out of his room and slamming the door before he had processed what it could mean. He had hoped that their conversation earlier would have made his brother realise that he was OK with his affection but Papyrus knew that it was probably wise to let things develop naturally before exploring anything sexual with him. The dating book he had swiped from the library warned of doing too much to fast with people you had just met, but he didn't quite know how to apply that to his current situation.

Papyrus was almost asleep when he began to hear noises coming from next door again. Any one else probably wouldn't have noticed the quiet calls, but recently he had become very good at picking out his brothers voice amidst the normal sounds of the night. He could tell Sans was trying to mask his voice using a pillow or something even though he had told him he could hear his moans through the wall. He knew it was an attempt to keep quiet for his own benefit, or maybe just out of habit...maybe even Sans was still shy about the whole thing. Papyrus sighed, the noises were making his own magic respond almost immediately. He wanted Sans there with him to tell him he didn't have to hide any more... to hold him him close, to kiss him and _Help him?_. 

Papyrus could feel his cheeks get hot and his magic gather faster as he continued that line of thought. He'd touched himself over his big brother before, a few times in fact, but now the reality of them being intimate was a possibility he felt his imagination run wild. He thought about how sans would kiss him hard, pushing him down on the bed his hands leaving light touches across his ribcage, telling him how much he wanted him. No matter how much Papyrus would scold his brother's colourful language in every day situations he secretly wanted to hear all the lewd things Sans could think of doing to him. Contrary to popular opinion he wasn't as naive as he wanted people to think, and he craved being forced to drop his 'standards'. Papyrus tried to mimic what the Sans in his imagination was doing by ghosting his fingers up his shirt with one had while the other hand slowly went to grasp at the magic gathering under his shorts. 

To his surprise his hand didn't come across the usual manifestation of his magic. Rather than the usual solid object he had found previously there was instead a smaller mound of magic. He had read that monsters like him who used magic as sexual expression were able to from a variety of different parts and since he was still knew to the whole experience he was instantly curious. He tentatively brushed against it with his fingers; It was hot to touch, wet and oh-so-sensitive. He thought back to his dating book, some of the later chapters were quite descriptive in monster biology, and remembered this type of genitalia was commonly referred to as a pussy. The feelings he was experiencing while touching himself were familiar yet different; his careful exploring causing small whimpers to escape and join in with the muffled groans that were growing in volume. Papyrus realised that under the slick folds there was some form of an entrance and something clicked in his head; his magic was responding to accommodate his brother's now it had realised sex was a very real possibility. He could feel his magic pulse at the realisation and he gave into the base urges that were battling for control as he inserted his finger into the opening.

Papyrus couldn't contain the moan that ripped from his throat at the penetration. He immediately regretted not using his other hand to muffle his cries when he heard sans pause next door. The problem was that it felt good, _So good_ and even moving his finger to pull out caused him to cry out again and made his legs tremble. A flash of recklessness passed through his thoughts; Sans had already heard him and knew what he was doing so why not continue? He set up a slow rhythm with his inserted finger, pushing in slightly further into his warmth each time. He could hear Sans starting up again even louder, probably giving up on trying to muffle his cries too. His other hand had drifted down to join in the exploration of the new sensations this form was giving him. It seemed like everything down there was on fire with how hot and swollen it felt but nothing could of prepared him for when his finger tip brushed over a small bump on the outside.

The jolt of pleasure he received was unlike anything he had experienced and made him buck on the digit he had buried inside his pussy. Moans were spilling out his mouth as he continued to finger fuck himself while playing with the sensitive nub. It was a delicious cycle of jolts of pleasure from the bundle of nerves making his insides even more sensitive and causing his finger drive in further. It was so good but not quite enough, he wanted Sans instead. He could hear the renewed moans coming from his brothers room and he allowed his imagination to form an image of Sans between his legs, his fingers being replaced by his brother's own phalanges, and watching while Sans lined his own magic up to push inside him-

The thought toppled him over the edge with a shout, his finger inside continuing to work him as his walls spasmed , his other hand having stilled on top of the bundle of nerves causing it to throb as he rode it out. He could hear Sans voice build to crescendo which only prologued his own release as he pictured what his brothers face would look like contorted in pleasure. He eventually slowed to a stop as his shaky hands left his conjured genitals, he knew there would be a mess to clean but currently he could hardly move, reality coming crashing through on what they had just done. What was he meant to do? He didn't feel he could face his brother right now out of embarrassment, but he could feel his soul sinking as all he wanted to do was hold him in the afterglow. Sleep eventually took him and come the morning he thought seeing Sans would be awkward as hell, but the other surprisingly seemed to be his carefree self; it was as if nothing had happened. Papyrus was confused by it all initially but searching his feelings he was glad that there activities last night hadn't put a wedge between them as he feared. Plus, if he was completely honest, the idea of having an unspoken understanding between them to keep there night-time secret just made him hotter.

This was how it continued for a few days, both of them getting braver and louder as time went on. One night when he was practically crying out Sans' name in his flurry of moans and whimpers he heard a loud thud from the other side of the wall. It had initially made him jump before he realised his brothers moans were a lot louder and closer. He had tentatively approached the wall, shorts completely kicked off and hand still clutching between his legs. He was imagining the absolutely lewd image of his brother lent against the wall, eyes flickering in frustration as he fisted himself to completion. He lent against the same wall as he slipped a few digits inside, being so worked up by the sense of danger at being this close. He moaned in abandon at the new angle giving him new sensations, and the feeling of Sans being so close was not missed on him. He could hear so much more now - he could hear Sans' breathing hitching and the strings of curses he was muttering under his breath, _Stars he wished Sans would just smash through the wall and fuck him already_.

His climax approached quickly as he bent over further, spreading his legs and bucking his hips into flat surface of his carpals not even trying to mask the sound of his brother's name hissing through his teeth, reaching his peak when he heard Sans Moan his name back. He came with a shout and almost saw stars with the intensity it hit him. Still panting and riding through the waves while his head cleared he realised he should probably straighten up and back away to keep up there secrecy but he hadn't heard Sans leave either. It was as if they were both waiting to see if the other would say something in acknowledgement or if their game would continue. Papyrus waited a while, before he could no longer hear the other's breathing. Thinking the Sans must have moved or teleported away he breathed a soft goodnight only to hear one from the other side in return. Sans' voice was a low grumble, he could feel the frustration in the tone it made him shiver. He knew his brother was close to breaking and he couldn't help but want to tempt the beast. 

If he thought that was bad though, it got a million times worse when undyne had come to stay after blowing up her house in a cooking accident. The arrival threw a spanner in the works as technically Papyrus had a hand in how Undyne's situation came about. So although Undyne had insisted on sleeping on the couch he had persuaded her to take his room at least for the first few nights without thinking that would mean he would be bunking with Sans. _Damn his 'caring' nature._

When he informed his brother of the development he saw Sans came to the same conclusion he had about them sharing and immediately made an excuse to leave about cleaning up the mess that he called a bedroom. While Papyrus appreciated the gesture, he regretted putting them both in this situation considering their night-time shenanigans. They were still yet to breathe a word of it to each other in the waking hours and they couldn't do anything in secret tonight knowing very well how not soundproof that wall was. 

The first night he was sure neither of them slept, every time he thought he was dropping off and getting comfortable he felt his brother shift to try not touch him too much. Sans radiated a nervous energy and was practically glowing with magic all over as he struggled trying to keep everything under control. Papyrus wanted to comfort him and drag him into a hug but he felt it would only make the other worse. Plus the longer it went on the more the anxious energy rubbed off on him, and although he passed out for a few hours he awoke feeling on edge and he could tell Sans was no better. 

The second night however he had insisted on having his bedtime story, Papyrus had convinced himself that the break in there normal night-time routine was one of the reasons it had felt so awkward the night before. Since they were in the same bed for the story he decided to lay his head on his brothers chest while he listened. Sans had resisted at first, stiffening up and trying to advert his gaze but Papyrus had tried to be persistent, using his natural charm while looking up at Sans with a big smile. He knew it was a bit of dirty move on his part but if it broke a little bit of the awkwardness between them it was worth it. 

Sans eventually began to relax, moving one arm around papyrus's shoulder blades and curling him more onto his side more while he read. After he finished the story they stayed that way for a while just enjoying being close while drifting to sleep. Eventually before Papyrus shifted to his other side and with Sans still having his arm around him he followed suit, fitting into place as the big spoon and letting his arm came to wrap protectively around Papyrus' spine. 

Papyrus gasped softly at the contact. There was something incredibly satisfying about being held this way even though he was the taller of the two. It seems his noise hadn't gone unnoticed by his brother who tightened his hold on him slightly. At first he thought that Sans was mad at him for spoiling the innocent hug they were having with the way the atmosphere had shifted to become thick with tension. Papyrus felt flush with embarrassment from slipping up but he was hyper aware that his pelvis was about an inch from the one behind him and that Sans was breathing hard against him; all of which caused another whimper escape his teeth. He knew he wasn't helping the situation but he couldn't help it, his soul was fluttering and his body ached to be touched. He hated feeling like he had put them in an another awkward situation though, he had almost turned over to apologise when something wet and warm ran lightly up his top vertebra.

Papyrus knew they could form tongues from magic, he'd done it on occasion when tasting cooking but he never thought they could be used like _this_. He jerked in his brother's grasp at the shock and Sans took the opportunity to grind their pelvises together, resulting in more whimpers to fall from his mouth. Sans was trailing his tongue over him languidly in contrast to the hand lower down his spine that was moving across his ilium with a teasing speed, each digit of his hand spreading out and tracing lightly across the bone through his shorts. 

In the back of his mind he knew his previous reservations were screaming at him to stop but he couldn't help move his hips back into Sans shakily, searching for more of that delicious feeling of friction. He felt Sans gasp against him and rock back into him slowly, setting up a low rhythm of back and forth while continuing the motions of his tongue. Sans was treating Papyrus with such care,slowly building up like he was afraid Papyrus would run away if he moved to fast or held him too hard. Papyrus was past the point of wanting to take it slow though, he craved more of his touch as he felt his magic gathering between his legs and form his pussy. It didn't stop there though, the amount of magic he had built up seemed to take form all across his pelvis giving him more fleshy matter from the tops of thighs and a sizeable ass. Sans Seemed to notice immediately the change as he now gripped at the soft ecto-flesh surrounding his hips, kneading it against his phalanges and making Papyrus shiver from the sensations. Even through both of their clothing he could feel Sans had conjured magic of his own and with the continued thrusting he could feel it push against his cheeks. He wanted more, he wanted to feel sans against him fully so he shifted his leg up and position slightly so Sans would be able to be more on top of him and reach between his legs.

“fuck” sans breathed against his skull being the one to break the silence first, he griped Papyrus hard and let himself grind him further into the mattress. 

“Langu-Ah S-Sans” Papyrus had tried to speak but it just came out garbled as Sans thrust against him again, this time grazing Papyrus' folds with his cock through the fabric of his shorts. 

“shit- papy is that a pu-”

 

“YOU OK PAPYRUS!?” _oh no_. Undyne had heard something. He could hear Sans practically growl in frustration burying his head in the pillow as he scrambled to answer her.

“Y-YES SORRY UNDYNE. BAD DREAM, SANS WAS JUST MAKING SURE I WAS O-OK!” He blurted out, trying to sound as confident as ever.

“ OK PAPYRUS! I'M SURE SANS WILL TAKE GOOD CARE OF YOU!” 

“THANK YOU UNDYNE” Papyrus replied trying to ignore the chuckle it had pulled from sans when undyne spoke, though he couldn't help but smile himself. His brother was taking good care of him, _really good_ , it was a shame they couldn't continue.

Papyrus laid back down next to Sans who's face was still buried in the pillow. He lent into him lightly placing his teeth on the others skull in a kiss. Sans moved to lookup at him and he could have died happy just seeing the look on his face. His brother was flushed a bright blue, his eyes were lidded and Papyrus could see he still had his tongue conjured in his slightly open mouth. This gave Papyrus a great idea. He had been re-reading his dating book this week and he recalled that both monsters and humans liked to kiss using tongues too. Summoning his own while bringing their faces level he tentatively pressed their teeth together, opening his jaw slightly to brush his tongue across the front of his brothers teeth. Sans seemed to give in quickly, already being worked up from earlier and returned the kiss with enthusiasm, opening his mouth wider and wrapping his own tongue around Papyrus's. The kiss felt even better than Papyrus had imagined, thankful that his moans at the feeling were being swallowed into his brothers mouth as Sans wrapped his arms around him. He similar to that one time he had tried the alcohol at Grillby's bar, after loosing a bet to a very amused Sans, only this time it was his brother he was becoming intoxicated with. 

“your killing me paps” Sans whispered while pushing him away lightly, unlocking their mouths to pull Papyrus into a hug. This sparked confusion, was he hurting his brother somehow and not realising?

“W-What Sans? Did I Do Something Wrong?” 

“no paps, it's just hard to hold back around you. you've done nothing wrong, i just want you _so_ much” And with that Sans pulled him to his side before he could object further and held him tightly against his chest. Papyrus had so much he wanted to say but he knew they couldn't talk freely with the possibility of Undyne over hearing next door. Reluctantly he stayed quiet, although frustrated he couldn't help find comfort in his brothers embrace as he felt sleep take him.

Which brought him to today. When he woke Sans had already left, he vaguely remembered him leaving and muttering something about being back for dinner as he kissed him goodbye. When he had woken up fully he had gone downstairs to see Undyne was already up and finishing breakfast, Papyrus had noticed she had a packed bag next to her, though it only seemed to have a few items. Undyne had explained she was needed in the capital tomorrow anyway and thought that she would head off early today and give him some space in case he needed more rest after a bad nights sleep. She was out the door as soon as she had explained before Papyrus had a chance to reassure her she wasn't outstaying her welcome. He was sure she knew that but he couldn't help feel a bit guilty even if she probably just wanted to get ahead on her work. Papyrus tried not to take it personally. 

He spent the day cleaning up the house and catching up on his and his brother's laundry. He thought about popping out to re-calibrate his puzzles but since the last human had charmed him so much he had lost motivation in setting up traps. If all humans were like this one, he doubted that there would be much use for human traps in the future. He thought about running an idea past Undyne about making the puzzles more about fun and less about capturing, he was sure she would be on board considering her fondness for the human too. 

Papyrus moved into his bedroom in order to change the sheets and tidy for tonight. Even if nothing happened he still preferred to change the sheets every few days anyway, though he couldn't help but put on his favourite sheets, just in case. Undyne had left little mess which he appreciated, just a used mug and a neat pile of clothes on his dresser. Seeing the clothes he suddenly panicked and moved to his wardrobe. Papyrus knew how much more confident he felt in the correct clothing, and since he and his brother were alone and he was cooking dinner he supposed it could count as a date. The only problem was The Great Papyrus was not an outfit repeater, and he didn't want to wear something Sans had already seen, which limited his options. Looking back to his bed he noticed Undyne had left a pair of black leggings at the top of the pile. He and Undyne were the same height and he was sure she wouldn't mind... what harm could it cause by just seeing how they looked on him?

Pulling the leggings on he realised they didn't quite feel right, far too loose. _Of course, Undyne isn't just bones!_ he thought and tried to see if he could get his magic to pool and fill out like it had been doing last night. It was surprisingly easier than he expected, probably due to the fact his magic hadn't quite calmed down at all since being in bed with Sans. Papyrus picked out a loose fitting orange v-neck shirt to complete the look, the fact that it was a little short and would reveal glimpses of underneath if he moved too much not lost on him. He stood back to look at the reflection he was casting on his bedroom window; with his formed ecto-body filling out the leggings properly he couldn't help but admire that he looked good. He realised now as the fabric was clinging to his newly formed flesh that in all the excitement he had forgotten to add underwear to his ensemble. He went to go for a pair of pants but paused _No, Sans will probably like it more this way_ , just the thought had his cheeks flushed again and his magic begin prickling with excitement. 

_Tonight will be the one_

**Notes for the Chapter:**

> Sorry this is now going to be three parts instead of two but it would have been over double the length if it was just two parts, part three will be up in the next few days :)  
> Again thankyou for reading and any comments/feedback is greatly appreciated!


	3. Part 3, the final frontier.

**Summary for the Chapter:**

> Be warned, it doesn't take long for this to descend into filth.  
> But thank you again for all the lovely feedback, i hope this last part was worth the wait :)

Papyrus was just grabbing the plates to serve dinner on when he heard the front door open. _Perfect_ he thought while putting the first part of his plan for the evening into action. He knew Sans was only holding back on his account, and he wanted to make sure Sans knew he wanted him too. He had acquired the plates but decided on staying up on his toes 'reaching' for them until Sans came in, knowing full well his shirt was ridding up and exposing his legging clad ass. He heard Sans coming closer and drop his keys on the counter before spinning around with a grin on his face. He noticed his plan was working as Sans's eye lights were still focused down to where his ass had been rather than making eye contact. Papyrus couldn't help but feel pleased with himself that his teasing was having the desired effect, and the look he had caught on Sans's face had the first first whispers of lust making him shiver. He'd never felt like the object of anyone's passion before, it was thrilling and because it was Sans making that face he felt his magic stir in response. Maybe not wearing pants was a bad idea.

“OH HELLO SANS! SO GLAD YOU'RE HOME!” Papyrus exclaimed, not wanting the silence between them to slip to awkward. He wanted to tease to try and break his brother's resolve but not make the other feel uncomfortable. Sans snapped his attention up to Papyrus's face and gave him a effortless grin. Papyrus couldn't help but catch his blush deepening at that, Sans really was Unreasonably charming.

“hey papyrus, been working hard? you look tired” Sans asked while moving to lean against one of the kitchen counters.

“OH? N-NO SANS I'M FINE” Papyrus replied, puzzled. He didn't think he looked tired, he placed the plates down on the side and fidgeted with the bottom of his top.

“you sure? you look like you've been _hauling ass_ ” Sans winked at him flirtly, which almost caused Papyrus to forget the terrible joke he'd pulled on him. Almost.

“SANS! THAT'S SO LEWD!” Papyrus turned around to serve up their dinner with a frustrated huff. _Of course there would be a joke_ , but honestly he had used the excuse to turn around and hide the effects Sans's presence was having on him. Even in joke form he found it hard to keep cool hearing Sans talking like that.

“come on papyrus, you can't expect to wear that and me not notice” Sans had pushed off the counter and had come to stand behind him, wrapping his arms around him in a loose embrace “besides, you look good”

The sincere compliment made Papyrus almost forget what he was doing before popping the plates down and serving the pasta. He thought Sans would leave but instead he choose to stay behind him in the hug, seeming to sigh happily at having Papyrus near him. Papyrus didn't mind one bit, he was really enjoying the light contact through the thin layer of clothing on his sensitive flesh,but he tried to stay focused by starting a conversation. Sans was making sticking to his plan of slow seduction hard when all he wanted to do was have the end result. _after dinner, be patient_ he reminded himself.

“Undyne Is On Guard Duty At The Capital Tomorrow, She Won't Be Staying With Us Tonight”

“yeah i ran into her on the way, i know it's going to be just us tonight”

“YOU WERE AT THE CAPITAL TODAY TOO?”

“yeah, i actually ran into the human as well. you we're right about that kid. i just hope asgore sees it too.”

“WOWIE. I CAN'T BELIVE THE HUMAN HAS MADE IT THAT FAR!”

“yeah they're really something”

A lull in the conversation made papyrus realise he had finished serving a few minutes ago and was just fussing so he didn't have to break contact. This was nice and all but Papyrus wanted to let his intentions be known for the evening ahead. Feeling a wash of bravery he experimentally wiggled his hips back into his brother.. He was a fast learner and knew the effect that type of friction had on Sans after last night so hearing him gasp at the movement was exactly what Papyrus had wanted. He pretended not to notice, continuing for a few minutes while bending over the counter a bit further to move their dinner plates to a counter closer to the living room. He was aware that all of his movements were pushing his conjured flesh further into the others pelvis as the other made no movement to get out the way. Papyrus could feel the energy in the room shift as his Brother's own magic was taking solid form. He didn't have time to enjoy the feeling Sans's length against him properly before he felt himself being spun around firmly to look Sans in the face, Thankful he had already moved the plates as he was pressed into the counter firmly. 

_Shit._ He had known he had been teasing his brother but looking at him properly he could see the effects in full. Sans usual eye lights had faded into pinpricks, his whole face glowing in a soft blue haze originating in his left eye. Papyrus could tell his tongue was forming and there was even small beads of sweat on his skull from the effort of keeping it together, even though his brother was smaller the way he was towering over him right now made Sans appear bigger and much more intimidating. Papyrus found himself subconsciously widening his stance to allow the other to stand between his legs.

“papyrus” sans breathed against his exposed collar bone, leaning in further causing Papyrus to be sandwiched between the counter and the hot and inviting body before him.

“i'm really fucking close to loosing my restraint with you” Sans licked a trail up his cervical vertebrae and fisted his palms into the counter, visibly trying to keep his shaking under control.

“please paps, don't push me unless you're ready”

With that Sans drew back to look Papyrus properly, Searching his face for any signal that what they were doing was what Papyrus really wanted. Papyrus knew he couldn't rely on being able to forge words in the state he was in so he opted instead to bring their faces together in a heated kiss. This seemed to do the trick and snap the last of Sans's resolve as he groaned into his mouth, immediately deepening the kiss by snaking his tongue in. Papyrus let himself be lifted slightly so he was perched on the counter, the other's hands on his hips and grabbing and at his conjured flesh. He grasped at his brother's shoulders when their kiss broke, feeling sans grind into him while his tongue moved to lick a trail down his neck. Only he didn't stop there. Papyrus yelped as he felt the others teeth graze between the gaps of his clavicle sending jolts of pleasure down his spine. 

Sans chuckled darkly against him, moving his hands up to roam under Papyrus's shirt and graze lightly over his ribs. Papyrus hadn't planned on moaning so loudly with such little contact but it was like Sans knew exactly where to touch to pull sounds out of him. The thought that they hadn't even gone far but he was already so worked up made Papyrus's head spin. He felt himself being pushed down slightly and his legs being spread open as his brothers head moved lower, hands moving to hold his legs apart. Papyrus suddenly panicked that they were very much still in the kitchen.

“S-Sans! We're In The Kitchen We Cant-Ah” he pleaded when his brothers face was nearly level with his crotch, he had to lean up on his arms just to see him but was cut off when Sans moved his hands down as well to knead very close to his crotch. 

“why not papy? no one else is here. besides...”Sans brought one of his fingers down to lightly trace the outline of his pussy making Papyrus shiver “where else would i want to eat?”

Papyrus was left speechless as the devilish smirk Sans was sporting only grew with the sound of a distinctive rip of fabric. _Oh Stars!_ In one move Sans had managed to rip open the leggings and suddenly Papyrus was feeling very exposed with his legs spread open and his brothers face inches from his genitals.  
“fuck papy. how could you be keeping this sweet cunt a secret from me?” Sans nipped at the tender flesh on his inner thigh, causing any objections over language to be lost to a cry of pleasure. 

“and not wearing panties, i guess i underestimated how much you wanted this” Sans muttered teasingly. Papyrus had gone almost red with how flushed he was, everything Sans was saying being completely true. He wanted this. More than he'd ever admit out loud. _He wanted Sans to completely wreck him._ but he noticed his brother had paused making him come out of the lusty haze slightly.

“i just need to know you'll tell me if you want to stop ok?” Sans asked, sincerity and concern written all over his face. Papyrus almost melted on the spot. Even now when his brother had lost a lot of his control he wanted to make sure that Papyrus really was going to be ok with it all. He managed an enthusiastic nod before feeling that sinful tongue give a slow and long lick across his folds. Papyrus felt himself lean back further on his arms so he was almost laid on the counter as Sans continued to lick every inch of him, pausing to linger only when Papyrus would moan louder, as if he was mapping out his most sensitive points for future reference. Out of habit one of Papyrus had raised one of his hands to his mouth to try and muffle his cries but Sans noticed almost immediately and pulled back from him slightly, his warm breath still tickling the sensitive slit.

“no papyrus, don't try and hide. i've been waiting too long to hear you for real” Papyrus complied and lowered his hand down shakily, still uncertain. Sans rewarded him by extending his tongue and licking very deliberately at his clit whilst still keeping eye contact, Papyrus almost screamed in ecstasy.

“s-shit papy if you knew what those noises were doing to me” Sans moaned in between dragging his tongue all over the sensitive nub. Papyrus couldn't stop crying out even if he wanted too, Sans moans making vibrations rack his whole body.

"A-Ah Sannns!” 

"yes papy, tell me what you want"

“I-I-Starsss, Please S-Sans” 

“please what?”

"Please M-More"

"more? heh, something like this?" Sans drew his mouth back slightly to give him space to insert one of his phalanges, which to Papyrus's embarrassment slipped in very easily. _Stars_ if Papyrus had thought that his fingers had felt good they had nothing on feeling part of Sans inside of him. 

"Sannns! Yes, That feels S-So Good" 

"yeah? what about this" Papyrus felt the finger inside him shift to curl upwards and hit a sensitive spot inside him that had him seeing stars.

"Saaaans!"

"mmm i love hearing you say my name like that. keep going i'll make you feel amazing" Sans lowered his mouth back down to join the finger working up a steady rhythm. Papyrus let himself lie back fully while his brother worked him into a incoherent mess of moans. Sans meant what he said, answering Papyrus's moans with his own, slowly increasing the pace of his finger fucking and using his tongue to lap up everything Papyrus had to offer. He could feel the familiar pull of his orgasm building quickly as he bucked against the face between his legs. 

"Sans-Sans! I'm Gonna-Ahhh"

"mm papy, that's it come for me" Sans flicked his finger upward to graze against the same spot again. He was _So_ close. 

"Ahhhhh-SANNNS! I'M-" Sans moved his mouth up and pressed his tongue hard into the others clit, keeping the intense pace as Papyrus toppled over with a shout. He felt his eye sockets tear up at the edges over the intense feelings as Sans continued to work against him, determined to prolong the other's pleasure. 

When Sans finally pulled his head up he looked absolutely debauched, a mixture of drool and Papyrus's juices all over his face. Lust clouded Sans eyes as he deliberately dragged his tongue out and around his mouth to lap up the liquid, the image making Papyrus groan more, his magic refusing to calm down and dissipate. Sans hadn't removed his finger and was still working him slowly through all the aftershocks. Papyrus knew his brother would be good but _starrs_ Sans really knew what buttons to press. 

"you taste so good papy, here-" Sans removed the finger insider him only to raise it to Papyrus's mouth. Papyrus knew this type of behaviour was filthy but he had past caring, gladly accepting the intrusion in his mouth. Tasting himself was an odd sensation but doing this in front of Sans just made him hot. He made sure to sit up enough to look right into sans eyes as he wrapped his conjured tongue around his brother's finger, enjoying the small amount of control he had over him. Sans was flushed, mouth hanging slightly open as he was completely captivated by the display. 

"you're such a good boy, shit papy, have caught your breath yet?” Sans whispered as he removed his finger. Papyrus nodded, feeling his magic dripping at the promise of more. 

"good" Was the only he warning he got before being lifted of the side and flipped over so he was bent over the kitchen counter. 

"because you're really going to enjoy me fucking you"

He could feel Sans groping his ass with one hand while pulling down his own shorts with the other. It was like something primal had taken over Papyrus as he whined and pushed his hips back to try and feel the other. Sans rewarded him with grazing his length teasingly over papyrus's slit. _Stars_. Feeling his brother pressing against him with no obstruction of cloth was incredible. Sans's magic had a distinctive feel, he had noticed it faintly before with his brother's tongue, it was slightly cool but electric with energy. Sans continued to tease him, patience being a virtue that he had but Papyrus lacked. Papyrus was trying to move back against him and entice him in but it wasn't working as well as he hoped. He could hear his brother's low chuckle punctuated with gasps as he enjoyed the sensations of rubbing his length against him.

"Sans P-Please" 

"c'mon papy let me here you say it" Sans lined up and pushed the head of his cock at Papyrus' entrance, ready to go but holding papyrus's hips still to prevent him pushing back. 

"SAAANNS"

"I wanna hear how much you want me to make you scream" He teased grabbing at Papyrus's hips whilst mimicking a shallow thrusting movement but not actually entering him. Papyrus's resolve had vanished as he cried out, wanting nothing more but to feel that cock inside him. 

"SANS! I CAN'T! Nyehh Please Sans... Fuck Me AHHH- " Sans thrust in eagerly, managing to almost hilt himself on the first try. Papyrus was moving his arms frantically around the counter grabbing at anything he could find to anchor himself with. It felt amazing, he'd never felt anything like it. _So Full_. And it hurt surprisingly less than he thought it would. Sans had really taken the time to work him up perfectly so the only discomfort he felt was that it was unfamiliar. Sans wasn't moving inside but his hands were roaming all over Papyrus's conjured flesh. He was soothing him with touches even when Papyrus knew he would be trying his best to not just thrust into him. Papyrus rotated his hips slowly enjoying the feeling of Sans's length brushing against his inner walls. He could hear Sans moan softly at the feeling and begin to move in slow shallow thrusts to work through any discomfort Papyrus had left.

It wasn't long before Sans began a steady rhythm against him and Papyrus was turned into a writhing mess of moans on the counter. He tried to grab behind him to touch his brother but he felt Sans swiftly grab his arms together to restrain him. He knew he could have panicked at the sudden loss of freedom but it just felt right, the new sensations being too much for him to process and the anchor his brother was giving him being a welcome addition. The giving up of control giving him no option but to focus solely on how amazing he was feeling, moans continuing to fall from his parted mouth. One thrust Sans drew almost all the way out only to slam back into him hard making Papyrus cry out.

"papy, its so good your so tight, fuck! i've wanted you for so long – ahh" Sans panted between thrusts, increasing his pace much to Papyrus's delight. 

"Sans, please more faster ahhh-"

"yeah you like it hard huh? such a good boy" Sans's hand on his hip moved to reach between Papyrus's legs to stroke his clit in time with his thrusts. Papyrus was moaning incoherently, the ability to form words lost was almost lost on him. _Stars he was close._

"keep moaning like that papy, i wanna hear everything. I cant wait to feel you cum on my cock- f-fuck you're so wet" Sans thrusts were becoming jerky. He was close too. Papyrus vision was clouding as he reached his peak, feeling his magic gush between his legs and coating Sans. He felt a few more thrusts before Sans bottomed out, hilting himself as he came with Papyrus's name on his lips. He released his grip on papyrus's arms to embrace him from behind, still buried deep inside. 

They were both in a panting heap when they began to come back to reality, magic dissipating but the remnants still left behind. It was Papyrus who spoke first, a forgotten detail making itself known. 

“Sans”

“yeah paps?”

“The Leggings, T-They Weren't Actually Mine, I Had Borrowed Undyne's Clothes”

“shit. well i don't think she'll be wanting what's left of them back any time soon, they're in a _tear-able_ state” 

Sans couldn't help but giggle at his own joke. Before Papyrus had time to tell him off he found himself being lifted up and somehow landing on his bed with Sans snuggling in next to him. He knew that he would have to clean the kitchen and do something with their abandoned plates at some point but for now he was contented just to lie there and enjoy the warmth of his brothers embrace. _Finally_

**Notes for the Chapter:**

> Thank you for reading! I hope it's ok and reads well, i had alot of fun writing it but if you have any feedback let me know! hope you all enjoyed the last part! <3

**Author's Note:**

> Thank You For Reading! This is my first post for undertale, my first fanfiction in a few years so any comments welcome, i'm a bit rusty! <3


End file.
